>> To save time, could the database pull the zip code or city information when a member adds a plant to their list?
That would be awesome! Would that be thousands of data point, or millions?
Maybe that should be more like a search feature than a static list. You would ask by State, county, city or ZIP code, and get a number expressing how many people there already said they "have" that plant.
As long as we're asking for the sun, the moon, the stars AND several nearby galaxies, I would ask if such a search could be done either by cultivar or by species. A rare cultivar might have only 1-2 members even trying to grow it, but knowing where the species thrives would give a good clue about one specific cultivar.
Of course, it breaks down when a member lives or grows in more than one location ... or "HAS" the plant in a greenhouse or indoors ... or jumps through hoops to keep it alive through the winter SOME years ...
Still, it would have a lot of value because the number of "zone pushing zealots" will usually be much smaller than the number of people who grow mostly plants that can live without huge papmpering.
>> But that's not as good as having a collection of: "I have grown this plant in the ground and it performed well for me."
True. Maybe the auto-populated list could be called "where people HAVE this plant" and the hand-entered list could be called "places where this plant THRIVED", or was recommended.